1. Field of the Invention
The present invention relates to a communication system for transmitting/receiving information to/from a network, a communication terminal and an operating equipment included in the communication system, and communication control method thereof.
2. Related Background Art
A mobile station, such as a cellular-phone, as an example of a communication terminal which transmits/receives information to/from a network, comprises operating equipments which can operate information to be transmitted/received to/from the base station of the network, and operating equipments which are connected to outside the mobile station and can operate information to be transmitted/received to/from the base station, wherein communication terminal control means for deciding an operating equipment which operates information to be transmitted/received to/from the base station out of these operating equipments is further comprised.
A mode for the communication terminal control means to decide the operating equipment is deciding an operating equipment which matches the bearer of an incoming call, which is specified by the incoming bearer information included in the setup message transmitted from the base station, as an operating equipment for operating information to be transmitted/received to/from the base station based on the predetermined priority and arrangement, and releasing the operating equipments other than the decided operating equipment so that these operating equipments cannot operate information.
In other words, when the incoming bearer is a “unrestricted digital communication”, and when a bearer whereby communication is actually performed is also decided as “unrestricted digital communication”, operating equipments other than the operating equipment which outputs a first call confirm request messages for accepting an incoming call with the bearer of “unrestricted digital communication”, such as an operating equipment which outputs a second call confirm request messages for accepting the incoming call with a bearer of “sound and video communication”, are released. In the present description, a bearer is specified by the combination of the information transfer capability (ITC), communication quality, coding system, communication speed, and other factors. Therefore even if the bearer service type is “unrestricted digital communication”, the bearer may be handled as a different bearer, such as “unrestricted digital communication 1” or “unrestricted digital communication 2”, depending on the difference of the communication quality thereof. Therefore the case when a bearer is different in the present description includes the case when the bearers are different, such as “unrestricted digital communication” and “sound and video communication”, and the case when the bearers are different depending on the difference in communication quality, such as “unrestricted digital communication 1” and “unrestricted digital communication 2”.
When the communication terminal control means of the mobile station decides a bearer whereby communication is actually performed, the incoming bearer and the bearer whereby communication is actually performed, may differ. In the case of the above example, even if the incoming bearer is “unrestricted digital communication”, the “sound and video communication” bearer may be decided due to certain factors. In such a case, for a conventional mobile station, operating equipments other than an operating equipment which outputs the second call confirm request messages for accepting an incoming call with a bearer of “sound and video communication”, are released, so an operating equipment which can support a bearer of “sound and video communication” may not be decided as an operating equipment which operates information, and in such a case, the choices on deciding an operating equipment which operates information are narrowed.
With the foregoing in view, it is an object of the present invention to provide a communication terminal, operating equipment, communication system, and communication control method which can increase the flexibility in selecting operating equipments when an operating equipment for operating information to be transmitted/received to/from a network is decided.